The modern communications era has brought about a tremendous expansion of communication networks. Wireless and mobile networking technologies have addressed related consumer demands, while providing more flexibility and immediacy of information transfer. Radio communication systems, such as Universal Terrestrial Radio Access Network (UTRAN), Evolved UTRAN (E-UTRAN), Global System for Mobile Communication (GSM)/Enhanced Data Rate for GSM Evolution (EDGE) Radio Access Network (GERAN), High-Speed Packet Access (HSPA) network and etc, provide users with the convenience of mobility along with a rich set of services and features. This convenience has spawned significant adoption by an ever growing number of consumers as an accepted mode of communication for business and personal uses. To promote greater adoption, the telecommunication industry, from manufacturers to service providers, has agreed at great expense and effort to develop standards for communication protocols that underlie the various services and features. One area of effort involves the key derivation to ensure security, continuity and efficiency of services, especially during a handover between networks with different bearer supports.